Topic: PLEASE HELP - Father is principal applicant - (F4 VISA)

PLEASE HELP - Father is principal applicant - (F4 VISA) Hello - July 2016 - Welcome letter from NVC saying case is ready. Father then submits a I601A - waiver approved, later gets a cover letter from NVC which states what documents are required by the principal applicant and that derivatives 2,3,4 need to submit a DS 260. We move forward with my father's case and he gets an interview for June 2018, returns to the US in Aug 2018 with his greencard approved. Once he returns, we start applying for I601 waivers for Derivatives 2,3,4. waivers approved, we submit the request for a DS260. Ds260 submitted and absolutely no response from NVC/ embassy. I submitted multiple inquiries to NVC and USTravel docs, there has not been one response that was useful. I recently noticed that the DS260 for derivatives 2,3,4 was marked as "Accompany". Im not sure if it needed to be marked as "Follow to join" or if thats whats causing an issue. Now, traveldocs support said we need to schedule our own interviews. Please help! Should i update DS260? Who should i call?